This application relates to optical resonators such as micro resonators and their fabrication.
Optical materials may contain certain impurities that absorb light and thus cause undesired optical losses. As an example, many compounds having the chemical group OH are optically absorbing at the optical wavelengths in the infrared region including the 1.3 microns 1.55 microns for optical communications and other applications. Examples of such compounds include water (H2O) and various hydroxyl radicals. Therefore, it is desirable to reduce the OH content in optical components and devices for optical applications in the IR spectral range.